The avenues make up the Portland Transit Mall, and traverse through Old Town, Chinatown, and Portland State University.

See Slides: The 10 Greatest Streets in the U.S.

APA judged streets on form and composition, character and personality, and environment and sustainable practices.

The revitalization and renovation made along the Portland Transit Mall as part of the MAX Green Line extension helped earn 5th and 6th Avenues a spot on the list, as well as the 2009 Portland Mall Revitalization Project, which renovated 40 storefronts.

Portland's East Coast sibling, Portland, Maine, also made the list for its Congress Street.

Banner Photo Credit: iStock

Related Slideshow: The 10 Greatest Streets in the U.S.

The American Planning Association named Portland's 5th and 6th Avenues as one of the 10 greatest streets in the nation in 2014. See which other streets made the list.